Roller Cone Drill Bit With Enhanced Debris Diverter Grooves

Abstract

A roller cone drill bit having a bit body with at least one support arm extending from the bit body. Each support arm may have an interior surface and exterior surface with an associated spindle extending from the interior surface. A respective cone assembly may be rotatably disposed on each spindle. A gap formed between interior portions of each cone assembly and exterior portions of the associated spindle with a fluid seal disposed in the gap to block fluid flow therethrough. Each cone assembly includes a generally circular back surface disposed adjacent to the interior surface of the associated support arm. A flow diverter groove formed in the interior surface of each support arm spaced from the associated spindle. Each diverter groove having a variable geometry to enhance the flow of fluid containing downhole debris away from the associated real assembly, and each diverter groove having a variable geometry.

1 . A roller cone drill-bit comprising:
 a bit body having at least one support arm extending therefrom;   each support arm having a leading edge and a trailing edge;   each support arm having a first, interior surface with a spindle extending therefrom;   an associated cone assembly having a cavity formed therein;   the cavity defined in part by interior surfaces sized to receive corresponding exterior surfaces formed on the spindle;   a respective bearing structure disposed between exterior surfaces of each spindle and interior surfaces of each cone assembly;   a fluid seal disposed in a first, generally cylindrical gap formed between interior portions of each cone assembly and exterior portions of the associated spindle;   a diverter groove formed on the interior surface of each support arm spaced from the associated spindle;   each diverter groove extending from the leading edge to the trailing edge of the associated support arm;   each diverter groove operable to direct fluid containing debris away from the associated fluid seal; and   each diverter groove having an increasing cross-sectional area extending from the leading edge to the trailing edge to minimize possible packing of debris in the respective diverter groove.   
   
   
       2 . The roller cone drill bit of  claim 1  wherein each diverter groove further comprises an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm. 
   
   
       3 . The roller cone drill bit of  claim 2  wherein each diverter groove further comprises:
 a generally u-shaped cross-section defined in part by a width and a height; and   the height of the cross-section of the diverter groove at the leading edge less than the height of the cross-section of the diverter groove at the trailing edge.   
   
   
       4 . The roller cone drill bit of  claim 2  further comprising:
 a cross-section defined in part by a width and a height; and   the height of the cross-section of the diverter groove relative to the backface of the associated cone assembly at the leading edge less than the height of the cross-section of the diverter groove at the trailing edge.   
   
   
       5 . The roller cone drill bit of  claim 2  further comprising:
 each diverter groove having a generally u-shaped cross-section defined in part by a width and a height;   the width of the cross-section of the diverter groove at the leading edge less than the width of the cross-section of the diverter groove at the trailing edge.   
   
   
       6 . The roller cone drill bit of  claim 1  further comprising:
 the diverter groove further comprising an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm;   the diverter groove having a generally u-shaped cross-section defined in part by a width and a height;   the height of the cross-section of the diverter groove at the leading edge smaller than the height of the cross-section of the diverter groove at the trailing edge; and   the width of the cross-section of the diverter groove at the leading edge smaller than the width of the cross-section at the trailing edge.   
   
   
       7 . The roller cone drill bit of  claim 1  further comprising:
 the diverter groove further comprising an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm;   the diverter groove having a generally u-shaped cross-section defined in part by a radius; and   the radius of the cross-section of the diverter groove at the leading edge less than the radius of the cross-section of the diverter groove at the trailing edge.   
   
   
       8 . The roller cone drill bit of  claim 1  wherein each diverter groove further comprises a cross-section selected from the group consisting of a generally u-shaped cross-section, a segment of a circle and a generally rectangular cross-section. 
   
   
       9 . The roller cone drill bit of  claim 1  further comprising each support arm having a second, exterior surface opposite from the first interior surface and the spindle. 
   
   
       10 . The roller cone drill bit of  claim 1  further comprising each diverter groove having a first edge and a second edge formed adjacent to the interior surface of the associated support arm. 
   
   
       11 . The roller cone drill bit of  claim 1  further comprising at least one diverter plug disposed on the interior surface of the associated support arm to assist in directing fluids containing debris into the respective diverter groove. 
   
   
       12 . A roller cone drill bit comprising:
 a bit body having three support arms extending therefrom;   each support arm having a leading edge and a trailing edge;   each support arm having a first, interior surface with a spindle extending therefrom;   an associated cone assembly having a cavity formed therein;   the cavity defined in part by interior surfaces sized to receive corresponding exterior surfaces formed on the spindle;   a respective bearing structure disposed between exterior surfaces of each spindle and interior surfaces of each cone assembly;   a fluid seal disposed in a first, generally cylindrical gap formed between interior portions of each cone assembly and exterior portions of the associated spindle;   a debris diverter groove formed on the interior surface of each support arm spaced from the associated spindle;   each debris diverter groove extending from the leading edge to the trailing edge of the associated support arm;   each debris diverter groove operable to direct fluid containing debris away from the associated fluid seal; and   each debris diverter groove having variations in dimensions and/or configuration to provide enhanced protection for associated fluid seals and bearing systems by diverting shale, formation cutting and other types of downhole debris away from such fluid seals and bearing systems.   
   
   
       13 . The roller cone drill bit of  claim 12  wherein each debris diverter groove further comprises an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm. 
   
   
       14 . The roller cone drill bit of  claim 13  wherein each debris diverter groove further comprises:
 a generally u-shaped cross-section defined in part by a width and a height; and   the height of the cross-section of the debris diverter groove at the leading edge less than the height of the cross-section of the debris diverter groove at the trailing edge.   
   
   
       15 . The roller cone drill bit of  claim 1  further comprising:
 a cross-section defined in part by a width and a height; and   the height of the cross-section of the diverter groove relative to the backface of the associated cone assembly at the leading edge less than the height of the cross-section of the diverter groove at the trailing edge.   
   
   
       16 . The roller cone drill bit of  claim 13  further comprising:
 each debris diverter groove having a generally u-shaped cross-section defined in part by a width and a height;   the width of the cross-section of the debris diverter groove at the leading edge less than the width of the cross-section of the debris diverter groove at the trailing edge.   
   
   
       17 . The roller cone drill bit of  claim 12  further comprising:
 the debris diverter groove further comprising an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm;   the debris diverter groove having a generally u-shaped cross-section defined in part by a width and a height;   the height of the cross-section of the debris diverter groove at the leading edge less than the height of the cross-section of the debris diverter groove at the trailing edge.   
   
   
       18 . The roller cone drill bit of  claim 12  further comprising:
 the debris diverter groove further comprising an inlet disposed proximate the leading edge of the associated support arm and an outlet disposed proximate the trailing edge of the associated support arm;   the debris diverter groove having a generally u-shaped cross-section defined in part by a width and a height;   the height of the cross-section of the debris diverter groove at the leading edge less than the height of the cross-section of the debris diverter groove at the trailing edge.   
   
   
       19 . The roller cone drill bit of  claim 12  wherein each debris diverter groove further comprises a cross-section selected from the group consisting of a generally u-shaped cross-section, a generally c-shaped cross-section, and a generally rectangular cross-section. 
   
   
       20 . The roller cone drill bit of  claim 12  further comprising each support arm having a second, exterior surface opposite from the first interior surface and the spindle. 
   
   
       21 . The roller cone drill bit of  claim 12  further comprising each debris diverter groove having a first edge and a second edge formed adjacent to the interior surface of the associated support arm. 
   
   
       22 . The roller cone drill bit of  claim 12  further comprising at least one diverter plug disposed on the interior surface of the associated support arm to assist in directing fluids containing debris into the respective debris diverter groove. 
   
   
       23 . A method of forming a roller cone drill bit having enhanced protection for associated fluid seals comprising:
 forming a bit body having a first end operable to be releasably engaged with a drill string and at least one support arm extending from a second end of the bit body;   forming each support arm with a first interior surface and a respective spindle extending inwardly from the associated support arm;   forming a cone assembly with an internal cavity having interior surfaces sized to receive a bearing structure associated with the respective spindle;   installing a fluid seal in a generally cylindrical gap formed between interior portions of each cone assembly and exterior portions of the respective spindle; and   forming a diverter groove on the interior surface of each support arm spaced from the respective spindle.   
   
   
       24 . The method of  claim 23  further comprising forming each diverter groove having variations in dimensions and/or configuration to provide enhanced protection for associated fluid seals and bearing systems by diverting shale, formation cutting and other types of downhole debris away from such fluid seals and bearing systems. 
   
   
       25 . The method of  claim 23  further comprising forming each diverter groove having a depth which increases relative to a backface of the associated cone assembly. 
   
   
       26 . The method of  claim 23  further comprising installing at least one diverter plug in the interior surface of the associate support arm proximate the diverter groove to assist in directing fluids containing debris into the associated diverter groove.